1. Field of the Invention
The present invention relates to a dispenser for dissolving and dispensing a soluble compound from a container into a stream of liquid such as water.
2. Description of the Related Art
The key to beautiful, healthy lawns and gardens is the proper application of fertilizer. The fertilizing of garden plants and lawn grass has always presented a problem to homeowners because of the difficulty in evenly applying the proper amount of fertilizer to the plants or grass.
Typically, solid fertilizer in granular form is spread on the ground with a rotary spreader. The application of the solid fertilizer oftentimes results in an uneven distribution over the ground area, resulting in the burning of patches of the lawn or damage to the plants. Heavy rains will often carry the fertilizer off and it will be lost and wasted. The uneven spreading of solid fertilizer causes an oversupply of fertilizer being provided at certain places, which is harmful to the plant, and at other places, an insufficient amount of fertilizer is distributed which fails to properly nourish the plants.
More recently, a popular fertilizer apparatus is a hand-held sprayer which attaches to the end of a garden hose. A water soluble concentrate chemical fertilizer is placed in a canister of the sprayer. The garden hose is connected to a cap member having a throughbore extending therethrough. The throughbore has entrance and exit ends. The canister is attached to the bottom of the cap member. Typically, an inlet orifice and an outlet orifice provide fluid communication between the throughbore and the canister attached to the cap member. Water is supplied through the garden hose to the throughbore of the cap member. A portion of the water stream is allowed to flow directly through the throughbore and exit the cap member. The remaining portion of the water stream is diverted into the canister by a flow restriction device, such as a venturi plug, located in the throughbore between the inlet and outlet orifices. The water diverted into the canister through the inlet orifice dissolves the fertilizer. The canister fills with water dissolving all of the soluble fertilizer. The liquid fertilizer solution is then drawn out of the canister through the outlet orifice by the venturi effect into the stream of water passing directly through the throughbore. One such hand-held sprayer is the Miracle-Gro Lawn & Garden Feeder by Sterns Miracle-Gro Products, Inc. The main drawback to this type of apparatus and method is that it requires a gardener to manually wave the sprayer back and forth, thus increasing the opportunity for poor lawn coverage. Additionally, the manual hand-held sprayer apparatus is tedious for the person using the sprayer. Furthermore, the gardener is required to hold the sprayer during use which often times will be used during the hot summer months. An automatic-type "hands free" apparatus that reduces or eliminates the requirement of gardener participation is desirable.
It is generally known in the prior art to provide devices which attach to water sprinklers or delivery systems for adding desirable compounds to the water passing through the system. The compounds are not limited to fertilizers but may also include pesticides, detergents or other water soluble compounds.
The prior art devices typically utilize a container having a cap member which is connected to a hose or other conduit through which the water is delivered. The cap member has a throughbore through which the water travels on its way to the sprinkler. The container is adapted to contain the soluble compound to be dissolved in the water. A small orifice in the cap member fluidably connects the container to the throughbore. A venturi plug in the throughbore of the cap member downstream of the small orifice serves to backpressure the water upstream of the venturi plug. The venturi plug diverts a small portion of the water stream through the small orifice into the container to dissolve and mix with the soluble compound therein. Downstream of the venturi plug there typically is a large orifice connecting the throughbore with the container. As is well known in the art, the reduced fluid pressure at downstream side of the venturi plug draws liquid from the container through the large orifice and into the stream passing through the throughbore. The resulting mixture is then carried downstream to the sprinkler.
The above-mentioned prior art devices rely on the well-known venturi principles and thus teach an obstruction to the flow of water between the small orifice and the large orifice resulting in a pressure differential between the orifices. The obstructions shown in the prior art include a restricted throughbore between the small and large orifices. See, for example, U.S. Pat. Nos. 5,133,498; 4,941,616; 4,901,923; 4,385,034; 4,333,493; 3,260,464; 3,194,444; 2,302,799; and 1,964,576.
It has been found that the venturi-type devices result in a significant fluid pressure drop at the outlet end of the device. The reduced pressure delivered to the sprinkler reduces the effectiveness of the sprinkler. Thus, the sprinkler covers a reduced surface area and, depending on the type of sprinkler being used, may cause it not to function properly. Since there are several types of sprinklers which require various operating pressures, it is desirable to have a dispensing apparatus which minimizes the fluid pressure drop through the apparatus.
It is further desirable to have a dispensing apparatus for use with underground sprinkler systems, soaker hoses or sprinkler hoses. Soaker and sprinkler hoses are capped at one end. Soaker hoses are porous and allow water to ooze or seep through the hose along its entire length. Sprinkler hoses have pin holes along its length which allow the water to spray the surrounding area with a fine spray or mist.
A general problem encountered in conjunction with the prior art devices is the complexity of the devices and the resulting cost to manufacture such devices. It is desirable to have an apparatus for dissolving and dispensing soluble compounds which is simple to operate, inexpensive to manufacture, and having the versatility to be used with virtually any type of watering apparatus or system without detrimental effect.